Existing technologies for cloning and recombination of genetic material enable construction of arbitrary DNA sequences. However, these techniques are time-consuming and can be rate-limiting because of the need for multiple sequential steps. The transformation of an existing plasmid into a bacterial host strain can be done rapidly and reliably when a selection marker such as ampicillin is used, however several limitations exist, such as: the number of different plasmids that can be co-transformed is limited by the choice of selection markers and compatible origins of replication; plasmids are less stable than chromosomal DNA and are difficult to maintain indefinitely without mutations occurring; and cistronic interactions cannot be designed since each new nucleotide sequence added is on an unconnected DNA molecule.